Appearing on MSNBC’s Morning Joe, presidential historian Michael Beschloss marveled at former Presidents George W. Bush and Barack Obama publicly denouncing President Donald Trump — albeit without mentioning his name– saying it is a huge departure in presidential decorum.

Host Joe Scarborough suggested that the two ex-presidents — along with Sen. John McCain (R-AZ) earlier in the week — have no choice but to go after the “heart of Trumpism” that promotes bigotry.

“Michael, you had a very good and unusual scene yesterday,” Scarborough said. “Many former presidents, especially if their last names are Bush. don’t even talk about their successors in a negative way. George W. Bush for the most part bit his tongue for eight years. But George W. Bush, yesterday you had President Bush — a member of the same party of the sitting president — and Barack Obama, obviously attacking the sitting president on the same day on his brand of politics.”

“George W. Bush debating bigotry and lies and isolationism,” the MSNBC host continued. “This speech was aimed directly at the heart of Trumpism.”

“Totally,” Beschloss agreed. “And, Joe, it was unusual, you’re right, the Bushes don’t like to do this. George Bush 41 wrote Bill Clinton a letter on Inaugural Day in 1993, saying ‘I will leave you alone — don’t have to worry about my criticizing you.'” ...